Guillermo Del Toro has been accused of copying the plot of his film The Shape Of Water from the work of a Pulitzer prize-winning playwright.

With 13 nominations, The Shape of Water is the most heavily recognized film at this year’s (18) Academy Awards, earning nods for Best Director, Best Picture, and Best Original Screenplay recognition for Guillermo and his co-writer Vanessa Taylor.

However, the son of the late playwright Paul Zindel has accused Guillermo del Toro of using his work without credit as the plot of the film, which follows a cleaner in a laboratory who falls in love with a sea creature, bears striking similarities to Zindel’s 1969 play Let Me Hear You Whisper.

“We are shocked that a major studio could make a film so obviously derived from my late father’s work without anyone recognizing it and coming to us for the rights,” David Zindel, who runs his father’s estate, told The Guardian via email.

Let Me Hear You Whisper, which was adapted for TV in 1969, features a female janitor in a research laboratory who bonds with a captive dolphin.

A spokesperson for the Fox Searchlight studio, which is releasing The Shape of Water, has denied the Zindel family’s plagiarism claims.

As well as earning Oscars recognition in numerous technical categories, The Shape of Water’s cast also received nods, with Sally Hawkins up for Best Actress and castmates Octavia Spencer and Richard Jenkins

The Shape of Water has been presented as an original idea, but Guillermo has also been accused of borrowing ideas from The Space Between Us, a Dutch short film released in 2015.

After a screening with Guillermo organized by the Netherlands Film Academy to discuss the comparisons, it concluded that the director had not stolen from the short, saying in a statement that the two works “have their own very different identities” and were “not in any conceivable way interlinked or related”.

Denying he stole ideas from the Dutch movie, Guillermo told the website Hollywood Elsewhere, “What is funny is that I have two movies, Hellboy and Hellboy II: The Golden Army, with an aquatic creature inside a super-secret tank in a large laboratory…so that (concept) is not exactly in the province of exclusivity.”